1. Field of the Invention
This invention relates to a catalytic method for the conjoint production of 2-methyl-diazabicyclo-(2.2.2.)-octane(2-methyl-triethylenediamine) and N-allyl piperazine. More particularly, this invention relates to a catalytic method for the conjoint manufacture of 2-methyl-triethylenediamine (MTEDA) and allyl pierazine from N-hydroxypropyl piperazine. Still more particularly, this invention is directed to the use of a catalyst composed of pellets of titania to which a minor amount of phosphorus (0.5 to 7 wt. %) has been thermally chemically bonded in the form of phosphate linkages to catalyze a continuous process for the conjoint manufacture of 2-methyl triethylenediamine and allyl piperazine from N-hydroxypropyl piperazine.
2. Prior Art
The catalysts used in the practice of the process of the present invention are disclosed in Vanderpool U.S. Pat. No. 4,588,842, a division of abandoned Vanderpool U.S. patent application Ser. No. 455,160, filed Jan. 3, 1983, upon which is based European patent application Ser. No. 83,307,520.3 published Aug. 28, 1984, wherein they are disclosed as useful in promoting the reaction of ethylenediamine with ethanolamine to provide essentially linear polyethylenepolyamine reaction products. Minor quantities of cyclic products are also formed.
It has heretofore been proposed to manufacture C-methyl triethylene diamine from a variety of substituted piperazine feedstocks by using appropriate catalysts.
For example, Nieh U.S. Pat. No. 4,092,316 discloses a process for the preparation of C-methyl triethylene diamine (MTEDA) by a liquid phase process wherein a suitable feedstock such as N-(2-hydroxyethyl)-2-methyl piperazine, N-hydroxyethyl)-3-methyl piperazine, N,N'-(di-2-hydroxyethyl)-2-methyl piperazine, N-(hydroxypropyl)piperazine, etc., is heated in the presence of a pentavalent acidic phosphorous compound.
Murakomi et al. U.S. Pat. No. 3,956,329 discloses a process for the dihydrocyclization of nitrogencontaining heterocyclic compounds such as N-hydroxypropyl piperazine to 2-methyltriethylene diamine using a zeolite catalyst.
Czechoslovakian Pat. No. 139,281 to Jezo et al. is directed to the thermal decomposition of 1,4-bis(2-hydroxyalkyl) piperazines in the presence of metal alcoholates such as (MeO).sub.2 Mg.
Other procedures are known for the preparation of C-alkyl substituted diazabicyclo-(2,2,2)-octanes by catalytically cyclizing certain substituted piperazine compounds, such as N-hydroxyethyl-methylpiperazines, N,N'-dihydroxyethylmethylpiperazines, etc., in the presence of very specific types of catalysts. Generally, such known procedures are vapor phase reactions which are carried out by contacting the vapors of the substituted piperazine feedstock employed with the acidic-type catalyst at temperatures in excess of about 250.degree. C. to about 500.degree. C. For example, U.S. Pat. No. 3,167,518 to Farkas et al. discloses a method for preparing 2-methyl diazabicyclo-(2,2,2)-octane by cyclodehydrating the reaction product of 2-methylpiperazine with at least an equal molar quantity of ethylene oxide in vapor phase over an active silicious cracking catalyst. More particularly, it is disclosed that the vapor phase cyclodehydration reaction is carried out by passing the ethoxylated 2-methylpiperazine reaction product vapors over a silica-alumina cracking catalyst at a temperature of 325.degree. C. to 425.degree. C.
U.S. Pat. No. 3,297,701 to Brader, Jr. et al. discloses that C-substituted diazabicyclo-(2,2,2)-octanes may be synthesized by the process of contacting a substituted piperazine compound, such as N-aminoethyl-C-alkyl-piperazines, N-hydroxyethyl-C-alkyl-pierazines, etc., in vapor phase with a metal phosphate catalyst in the presence of ammonia at a reaction temperature within the range of 250.degree. C. to about 500.degree. C.